Telephony.



G. A. BALS.

TELEPHONY.

APPLICATION FILED APR. 24, 1911.

Patented May 13, 1913.

2 sums-sum 1.

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wn/easeex h UNITED STATES PATENT OFFICE,

CHARLES A. BALS, OF CHICAGO, ILLINOIS, AS SIGNOR T0 GORWIN TELEPHONEMANUFACTURING COMPANY, A. CORPORATION OF ILLINOIS.

TELEPHONY.

Specification of Letters Patent.

Patented May 13,1913.

Application filed April 24, 1911. Serial No. 623,043.

T 0 all whom it may concern:

Be it known that I, CHARLES A. Bans, citizen of the United States,residing at Chicage, in the county of Cook andState of and saidtelephone lines; apparatus at said telephone station for setting saidselecting mechanism into operation and for holding the same when-atelephone line has had an extension selectively connected therewith atthe exchange; and switching mechanism whereby said apparatus may beinterchangeably associated with said telephone lines and whereby theselecting mechanism may be maintained in that condition in which atclcphone line and an extension are connected together through theagency of said selecting mechanism when said apparatus is trans ferredfromassociation with this latter telephone line to another telephoneline.

My invention in another of its aspects may be described as a telephonesystem including telephone lines extending to different exchanges; abattery at each exchange common to equipment there located; a trunk lineextending from one exchange to the other; link connecting mechanism atthe latter exchange for connecting the trurk line with telephone linesextending to the latter exchange; circuit connections whereby the commonbattery at one exchange may be brought into operative association withequipment at the other exchange; and means at the latter exchange fordisassociating the common battery thereat from the circuit establishedbetween lines byway of both exchanges and trunk line.

My invention in another of its aspects may be described as a tele honeexchange system including telephone lines extending to one exchange;link connecting mechanism at this exchange for uniting lines extendingto this exchange; telephone lines extending to a second exchange; atrunk line intervening between the exchanges whereby connection may beestablished between telephone lines extending to both exchanges; anoperators telephone outfit; and switching mechanism whereby saidoperators telephone outfit may be connected with the trunk lineindependent-1y of the link connecting mechanism and may be connectedwith the link connecting mechanism independently of the trunk line.

My invention in another of its aspects may he described as a telephonesystem including telephone lines exteniling to two exchanges; a trunkline extending between the exchanges whereby lines extending to bothexchanges may be connected for conversation; an o 'ierators telephoneoutfit at the 'ex change to which the trunk line extends; mechanism forassociating said operators telephone outfit telephonically with thetrunk line; mechanism for preventing the association ofsaid operatorstelephone outfit with the trunk line when connection has beenestablished between lines extending to said exchange by way of saidtrunk line and means for placing said mechanism beyond opcrators controlupon the establishment of connection between telephone lines extendingto the exchanges.

I will explain my invention more fully by reference to the accompanyingdrawings showing the preferred embodiment thereof and in which-- l igure1 illustrates a manual switch board system provided with link connectingmechanism adapted to unite lines extending to the manual exchaiwe, thejack end ofa trunk line being shown m Fig. 1, the balance of this trunkline being shown in Fig. 2 where it extends to an automatic exchangethat is diagrammatically indicated in this latter figure.

The manual exchange indicated in Fig. 1 may, for example, be considereda private branch exchange. But one telephone line 3-3 is shown though itis to be understood that many other telephone lines are mnbodied in theexchange illustrated by Fig. 1. The telephone line 3 extends from asubstation A that may be of any Well known or suitable type and whichterminates at a springja'ck 4: at the exchange, two talking jack springsconstituting the terminals of the'lines 3 which engage with suitableback contacts for loopingin a line signal 5 in serial relation with theline and for permitting the exclusion of this line signal from circuitwith the line when the jack springs are separated from their backcontactsupon the insertion of a plug of a link circuit, it beingunderstood that'the line signal 5 is included in circuit with a commonbattery 6 when the telephone receiver at station A is removed from itsswitch-hook, Link circuits are desirably vate branch exchange,

employed at the private branch exchange that have each a manuallycontrolled plug 7 at the answering end, and the manually controlled plug8 at the connecting end whereby lines extending from substationsdirectly to the private branch exchange may be directly connected bymeans of lin'kcircuits thus provided with answering andconnectingplugs 7and 8. The cord circuit .mechanism that is shown between the answeringand connect ng plugs 7 and 8 and which is illustrated between thestrands 9 and 10 of the 'cord circuit is well underlay mechanism is toremain inert, in accordance with the preferred embodiment of myinvention, when the link circuit is used in cooperation with the trunkline 17 in connecting telephone lines that extend to the exchanges shownin both views, for reasons which will appear and to which end a circuitopening key 18 may be employed for breaking the conductor that extendsfrom the common battery 6 to the link circuit. It is to be understoodthat I do not limit myself to'the type of link circuits shown. The relay15 has three armature switches, theouter two armature switches servingwhen attracted to bridge the operators telephone outfit 16 between thetalking strands of the link circuit, when the apparatus is in suchworking condition as to permit of this association I of said telephoneoutfit. Another relay 19 is employed to out the operators telephone outof circuit, the operators telephone being cutin circuit when a callingsubscriber is to be answered and 'being cut out of circuit when theconnecting end of the cord circuit that is in circuit with the callingsubscribers line ismanipulated to tomatic exchange connect the callingsubscribers line with a called line that extends to the private branchexchange.

If the operator at the branch exchange should for any reason desiretelephonic connection with the exchange illustrated in Fig. 2, suchoperator will depress the button 20 to cause it to occupyits alternateposition thereby to energize the relay 19 and transfer the connection ofthe uppermost contactof the key 20 and next to the lowermost contact ofsaid key whereby these terminals are connected with-the sides of thetrunk line 17 owing to the depression of the key 20, these trunk linesides being connected with the contacts that are engaged with theaforesaid contacts of the key 20 when said key is thus depressed. Thecircuit that is established through the relay 19 as a result of themanipulation of the connecting end 8 of the link circuit need not bedescribed as such is now well known to those skilled in the art. Thecircuit which is established through said relay as a consequence of thedepression of the key 2-0 may be traced from the grounded terminal ofthe relay 19, through the winding of said relay, the two middle contactsof the key 20, the inert armature switch of the relay 2l'and itscontact, to the upper terminal of the battery 6. When the operator atthe private branch exchange is through with her use of thetrunk line 17she will operate therestoring key 22to rclease the key 20 and allow itto assume the normal position illustrated whereby the cir cuit for therelay 19 willbe opened and the operators outfit 16 has its; circuitassociation with the link circuit at the private branch exchangerestored.

If the party whose line extends to the austood that I do not limitmyself to automatic exchanges) should desire telephonic connection witha party whose line extends to the private branch exchange a 'circuitwill automatically be established through the signal 23 that is locatedat the private. branch exchange in response to which signal the (thoughit is to be under-.

operator at the private branch exchange will manipulate her key 20 tobring her telephone outfit into circuit association with the trunk line17 in the manner which has been described. After having ascertained thewants of the calling automatic subscriber the operator at the privatebranch exchange will disconnect her telephone out,- fit from thetelephone line by pressing the releasing button 22, will insert theanswer ing plug 7 in the trunk line jack 24;- and ing tau-rent as, forexample, a battery 26 tl'irougli said signal. receiver 25, the switchhook at. the wanted pri "ate branch statlon, the sleeve spring of thepick at belonging to the line of said wanted private branch sta' theright hand winding of the supervisory relay 1.4-, the ringing circuitinterrupter switch spring 25) and the lower contact intermittentlyengaged therewith to battery 20. The rest of the operations that are toensue when the wanted private branch part-y responds and whenconversation has been concluded need not be described, such being clearto those skilled in the art.

It the party at a private branch exchange station should desireconnection with the party at. an automatic substation, such callingparty will signal the private branch operator in the usual way and suchoperator will ascertain the wants ot the calling party in the usual. wayand, in accordance with preferred practice, the calling party willtemporarily restore his receiver upon his switch hook to await thesignalv conveyed by his receiver 25 which will indicate to him that theprivate branch exchange operator has secured the wanted line. T heoperator, in order to secure the wanted line, selects a trunk line 17and operates a master switch key 30 individual to the selected trunkline for bringing the circuit interrupting or dial mechanism 31 intooperi'i'tive association with the selected trunk line in order that thewanted automatic station may automatically be selected and while I haveillustrated a 40 well. known dial mechanism for operating the selecting:mechanism at the automatic exchange, I do not wish to be limited to suchdial mechanism nor to the en'iployn'ient of selecting mechanism thatwill automatically connect the wanted line with the trunk line,

as I consider certainfeatures of my irivciition to be broadly new inconnection with means whereby the extension is automatically providedfor the trunk line whether or not such extension extends clear throughto the calling station. As the invention is exhibited the dial mechanism31 in its normal position serves to establish a direct connectionbetween the sides oi the trunk line for the purpose of holding theselecting mechanism in that position which it has been caused toassumein order to establish the desired extension for the trunk line and ifthe operator at the private branch exchange had no furco thcr use torthcdial mechanism she would allow it to remain in association with theselected trunk line tor the purpose of maintaininn the connectionbetween the sides of the trunk line for the purpose just stated.

55 It, however, the private branch operator should need the dial'mechanism 3.1. for the purpose oi selecting}; another automaticsubscriber she will operate another key 32 indi vidual to a sceomlselected trunk line, said key being so mechanically inter-related withthe first key 30 as to cause said key 30 to assume its normal positionin which a connect ion is established across the sides of the trunk line17 in substitution for the connection that was previously establishedbetween the sides (it said trunk line by way of the contacts Ill thatare closed when the dial mechanism is in normal position. The switch 3tthat causes impulses to be trans mitted over the trunk line 1.? isincluded in a circuit connection that. may be traced from the lower sideot the trunk line 17, the right hand contact spring of the depressed keyindividual to the trunk line, the contact engraced by this spring whenthe key 3:2 is depressed, the left. hand switch 9st of the dial 3t whenthis dial is oil" normal position, the contacts of the switch 3-1, thelet't hand contact spring of the de n'essed key 32, the contact engagingthe same, to the upper side of the trunk line 17. in this way but onedial mechanism may be employed for a group of trunks without disturbingthe connections that have been automatically established between thetrunks and thcextensions therct'rt'nn.

It the operator should desire to hold a trunk independently of the dialmechanism 31 and with the key mechanism 30, 32 in normal condition shewill depress the holding button 3.3 to establish a connection betweenthe sides of the trunk line. It is understood that the keys 30, 32 areindividual to different trunk lines and that the dial mechanism is madecommon to the trunk lines by way of the keys 3t), 32. The holdingcircuit connection established for holding a trunk line is traceablefrom the lower side of the trunk line 17, the lower contact .of the key3:"), the upper contact of this key, the fourth and third contacts fromthe left of the key 32 individual to the trunk line when this key isnormal, to the upper side of trunk line. It is not necessary to describethe operations which occur when the dial mechanism is actuated as suchare well known to those skilled in the art of automatic andsemi-automatic telephony.

After the wanted automatic subscrih r whose line has become connectedwith the trunk line 17 has been signaled in the usual way the operatorat the private branch exchange will insert the answering plug: T intothe trunk jack Z-l and will insert the connectingz, plug 8 in the jackof the private branch exchange {arty originating the call whereupon acircuit will be established through the signal receiver 25 at the call(ruminating station. which circuit hashithcrtobccn traced. When aconnection has thus been established through both exchanges the cordcircuit at the private branch exchange should be relieved of itsassociation with its relay equipment in order that the extension of thetrunk 'line established at the private branch exchange by means-of thecord-circuit connected withi'the trunk line ma be a mere metalliccontinuation of the tal 'ng sides ofthe trunk line and in order thatthiscondition may arise the key 18is operated to disconnect the battery 6from the cord circuit whereby the armature switches 27, 36 at thecalling end of the cord circuit-may remain normal,the armature switches37 at the answering end of the cord circuit being then normallyindependent of the battery 6.

The operator will manipulate the key 18gtodisconnect the battery 6 whenthe super- 'v-isory lamp 12-ceases to glow. By thus 20 cuit asupervisory or disconnect. lamp 38v stripping the battery 6 from thecord cirmay be associated with the trunk line .so.

as to be under the control of the private branch exchange partyconnected with the trunk line, circuit through this supervisory lamp 38being closed when the private tually become branch exchange party, Whohas now viran automatic exchange party by the removal of the battery 6,restores his receiver upon its switch hook, the armature of the relay 21that is thereupon deenergized completing the supervisory lamp circuit,such ci'rcuitbeing traceable from the grounded battery 6 through thereleased armature switch of the relay 21 to the grounded terminal of thelamp 38. The

relay 21is not included in circuit with the battery 6 but is included incircuit with the common battery at'the automatic exchange. The groundedterminal of the lamp 38 is disconnected from the lamp when the plug iswithdrawn from theiack 24 so as to exv tinguish the light at 38. Inaddition to the equality in the advantages which have been cited as a"re sult of the circuit opening operation of the key 18 I also preventthe battery at either exchange from discharging into the battery of theother exchange in the event of involtages of these batteries.

JWhere the private branch exchange party is a called party and anautomatic subscriber is a calling party I provide novel means'forgoverning the call signal device battery 6 and ground by 23 at theprivate branch operators position which includes electromagneticmechanism 39 having one coil inbridge of the trunk --line and in serieswith a condenser 40 in "the nected in bridge of the trunk line as a con-I plugged into switch will engage its contact and hold a circuit throughthe coil 11 thereby to. maintain circuit through the signal lamp 23 thatmay be traced from the grounded battery 6 through said left handarmature switch and its contact to the grounded terminal-of the lamp'23. The ringing current through the coil 39 is cut ofii' when theoperatorresponds, 1n a manner well known, whereupon circuit through therelay &1 is alone.

sequence ofwhich the left hand armature I relied upon to hold the lefthand armature switch attracted, this circuit being broken when theoperator plugs' in to the jack 24 thereby to open the circuit throughthe signal device 23-.

In night time, or any other time when it is desired to dispense with theservices of an operator at the private' branch exchange for the purposeof connecting automatic and private branch exchange ,parties, cordcircuits at the private branch exchange may be allowed to remain inconnection with private branch lines and automatic trunk lines. As aresult the signal devices 23 are excluded from circuit and the signalreceivers 25 at the private branch exchange stations are'subjectto thecontrol of the right hand armature switch associated with theelement'39, this right hand armature switch engaging its contact to closecircuit through the signal rece1vers 25 when the coils 39 are energized.The circuit thus established through a signal receiver 25 may be tracedfrom the battery 26 through said right hand armature switch and itscontact, a portion ofthe sleeve side of the associated trunk 17, thesleeve spring of'the jack 24, the sleeve of the plug inserted withinsaid jack, the armature switches 27, 37 and their normal contacts, thesleeve of the other plug, the sleeve spring of the jack receiving saidother plug, the switch hook at the substation having said signalreceiver '25, the lower contact of said switch hook, said signal receiver 25 back to the battery 26. It is understood'that thekey 18 isoperated to disconnect the battery 6 from any cord circuit that is thusallowed to remain in connection with the jacks of a trunk line and aprivate branch exchange line.- hen cord circuits are allowed normally toconnect trunk lines and private-branch lines, a private branch party maybe able to select an automatic subscribers station by means of adial'inthe well knownw'ay. Each private branch exchange party who is to havefacility for automatically calling an automatic exchange party, in theabsence of the operator at the private branch exchange, has a cordcircuit his line and the key 18 individual to such cord circuit isdepressed so as to remove the battery 6 from such cord circuit.

The automatic exchange equipment shown illustrated upon page 530.

While I have herein shown and particularly described the preferredembodiment of my invention I do not wish to be limited to the preciseequipment, circuit arrangement, and telephone exchange systems shown aschanges may readily be made without departing from the spirit of myinvention, but

llaving thus described my invention, I claim asnew and desireto secureby Letters Patent the follmving:

1. A. telephone exchange system including a plurality of telephone linesextending between an exchange and a telephone stat-ion; extensions forsaid telephone lines having terminals at the exchange; electromagneticselecting mechanism for effecting'connection between said extensions andsaid telephone lines; circuit breaking mechanism at said telephonestation for setting said selecting mechanism into operation and servingwhen at rest to establish connection between the. sides of the telephoneline with which it is associated to hold the selecting mechanism in thatposition in which a telephone line is connected through the agency ofsaid selecting mechanism with a telephone line extension; and switchingmechanism whereby said circuit breaking mechanism may be interchangeablyassociated with said telephone lines and whereby a connection isestablished between the sides of the telephone line from which thecircuit breaking mechanism is transferred in order to prevent thatoperation of the selecting mechanism associated with the line from whichthe circuit breaking mechanism s transferred that would cause theseparation between the telephone line and extension previously connectedby the selecting mechanism.

2. A telephone system including telephone lines extending to differentexchanges; a battery at each exchange common to equipment there located;a trunk line extending from one exchange-to the other; link connectingmechanism at the exchange to which the trunk line extends for connectingthe trunk line with telephone lines extending to this exchange; circuitconnections whereby the common battery at one exchange may be broughtinto direct operative association with clearing out or supervisoryequipment at the other exchange; and means at the exchange having theequipment with which the common battery is brought into operativeassociation for disassociating the common battery thereat from thecircuit established between lines by way of both exchanges and trunkline.

3. A telephone system including telephone lines extending to ditl'erentexchanges; a battery at each exchange common to equipment there located;a trunk line extending from one exchange to the other; link connectingmechanism at the exchange to which the trunk line extends for connectingthe trunk line with telephone lines extending to this exchange; circuitconnections whereby the common battery at one exchange may be buiughtinto direct operative association with clearing out or supervisoryequipment at the other exchange; and means for disassociating thebattery at one of the exchanges from the circuit established betweenlines by way of both exchanges and trunk line.

4-. A telephone system including telephone lines extending to differentexchanges; a battery at each exchange common to equipment there located;a trunk line extending from one exchange to the other; mechanism at theexchange to which the trunk line extends for connecting the trunk linewith tele phone lines extending to this exchange; circuit connectionswhereby the common battery at one exchange may be brought into directoperativeassociation with clearing out or supervisory equipment at theother exchange; and means at the exchange having the equipment withwhich the common battery is brought into operative association fordisassociating the common battery thereat from the circuit establishedbetween lines by way of both exchanges and trunk line.

5. A telephone system including telephone lines extending to differentexchanges; a battery at each exchange common to equipment there located;a trunk line exte ling from one exchange to the other; mechanism at theexchange to which the trunk line extends for connecting the trunk linewith telephone lines extending to this exchange; circuit connections"whereby the common battery at one exchange inay be brought into directoperative association with clearing out or supervisory equipment at theother exchange; and means for disassociating the battery at one of theex- 1 changes from the circuit established between in to both exchan esan o erators tele phone outfit; switching mechanism whereby saidoperators telephone outfit may be connected with the trunk lineindependently of the link connecting mechanism and may be connected withthe link connecting mechanism independently of the trunk line; and arelay governed by the switching mechanism employed to connect theoperators telephone with the trunk line and serving to shift theoperators telephone terminals from the link connecting mechanism to thetrunk line.

7. A telephone exchange system including telephone lines extending toone exchange; link connecting mechanism at this exchange vconnected withthe link connecting mechanism independently of the trunk line; and

relay mechanism adapted to be governed bythe link connecting mechanismfor control ling the association of' the operators tele phone outfitwith the link connecting mechanism and adapted also to be governed bythe aforesaid switching mechanism for con trolling the association ofsaid operators telephone outfit with the trunk line.

8. A telephone system including telephone lines extending to twoexchanges; a trunk line extending between the exchanges whereby linesextending to both exchanges may be connected for conversation; linkconnectors at one of the exchanges for unit ing lines extending theretoin telephonic connection; an operators telephone outfit at this exchangeadapted for telephonic association with said link connectors; mechanismwhereby said operators telephone outfit may be telephonically associatedwith the trunk line; mechanism for excluding the operators telephoneoutfit fromtelephonic association with the trunk line; and means forplacing said lattermechanism beyond the operators control upon theestablishment of connection between telephone lines extending to saidexchanges/by way of said trunk line and a link-connector.

9. A telephone system including telephone lines extending to twoexchanges; a trunk line extending from one exchange to the other wherebylines extending to both exchanges may be connected for conversation; an'operators telephone outfit at the exchange to which the trunk lineextends;

Copies of this patent, may be obtained for five cents each; byaddressing the Conlmissionerof Patents,

Washington. D. C,

mechanism for associatingsaid operators been established between linesextending to i said exchanges by way of said trunk line; and meansforplacing said latter mechanism beyond the operators control upon the establishment of connection between telephone lines extendin 'totheexchanges.

10-. A phone lines extending'to two exchanges; a trunk line extendingbetween said exchanges; a source of signaling current at one of saidexchanges; electro-magnetic mechanism at said exchange for includingsaid source of current in a signaling circuit, said electro-magneticmechanism having a winding included in circuit relation. with thetrunkiline; and means at the other exchange for energizing said windingwhereby signaling current at said other exchange need not directly beincluded in the signaling circuit at the first exchange.

11. A telephone system including teletelep one system includingtelephone lines extending to two difli'erent exchanges, a trunk lineextendingbetween said exchanges; a cord circuit at one of the exchangesadapted to connect telephone lines with the trunk line, said cordcircuit having electro-magnetically controlled cord circuit apparatus inassociation therewith; and means for disassociating said electromagnetically controlled cord circuit apparatus from the cord circuitwhen such cord circuit is to be used in connection withthe trunk linefor establishing connection between lines extending to the exchanges.

12. A telephone system including telephone lines extending to differentex-- changes; a trunk line extending from one exchange to the other;link connecting mechanism at the exchange to which the trunk lineextends for connecting the trunk line with telephone lines extending tothis exchange and also for connecting telephone lines extending to thisexchange; a battery;

and switching mechanism for bringing the battery into direct associationwith the clearing out or supervisory signaling apparatus related to anestablished connection at .both exchanges.

In witness whereof, I hereunto subscribe my name this eighth day ofApril A. D.,

, onantns A. Bails,

Witnesses:

G. L. GRAGG, ETTA L. WHITE.

